package com.it.you.base.map;

import org.junit.jupiter.api.Test;

import java.util.HashMap;
import java.util.Map;

public class HashMapTest1 {

    public static void main(String[] args) {
        Map map = new HashMap<String, String>();
        //map的key value 都可以为null
        map.put(null, null);
        System.out.println(map);
        System.out.println(map.get(null));
    }


    @Test
    public void test(){
        String a = "a";
        System.out.println(a.hashCode());
        int b = 97;
        System.out.println(Integer.hashCode(b));
    }
}
